Yup, the light on the roof definitely works! It isn't permanently mounted, however, so I take it off for regular street driving (to avoid hassles with the local police). It attaches via a magnetic base, and is powered by a wiring system that routes from in behind the dash, up the front pilar (hidden) and through the headliner, exiting by the sunroof. I put it on, hook it up and plug the power into the cig lighter and away I go! I use it for shows and parade type events, but I did use it on the Bellevue Mustang Roundup 2000 Pony Trails event.
The car was used at a local circle track to pace the bigger events back in the late 80's and early 90's so they had to wire it to run the lights then. Eventually I plan on installing a full strobe light system that will have flashers where the driving lights currently are, in the side markers and in the tail lights. That should REALLY grab some attention at shows.